i) Field of the Invention
The present invention relates to a heat exchanging device used for a freezer, an air-conditioner or the like and, more specifically, it relates to a heat exchanging device employing a heat exchanger which includes a single metal plate or two metal plates and a fluid channel positioned on the plate or between the plates for conducting a heat exchanging medium, the plate or plates with the fluid channel is bent into a winding like a coil.
ii) Description of the Prior Art
A heat exchanging device is disclosed in the U.S. Pat. No. 3,252,292 as a sheet-condenser 34, although not specifically explained. This type of condenser usually includes a single metal plate and a pipe bent into a serpentine curve and attached to the metal plate for conducting refrigerant. As shown in FIG. 2, the plate with the pipe is bent into a winding like a coil, so that the required space for installing the condenser is reduced.
For example, when the above-mentioned condenser is used in a refrigerator in which at least two condensing functions for a freezing device are required as in the case where two systems of compressor type refrigerant circuit are provided, the refrigerator 106 is provided with two condensers 100, 101 positioned in air channels 102, 103 formed independent of each other and provided with two independent air blowers 104, 105, as shown in FIG. 12.
With the above construction, a large space is required for forming the separate air channels or passage ways. As a result, the freezing device is large-sized, and two air blowers are required.
With the construction where a single air blower 104 is used as shown in FIG. 13, only a half of the flow rate of air is effectively used when one of the condensers is inactivated. This leads to inefficient operation.
With the construction where a single air blower 104 and a single air channel are provided and the condensers 100, 101 are connected in series with regard to the direction of flowing air, there arises a problem that the temperature of incoming air to the condenser 100 positioned on the leeward is higher than that of the condenser 101, so that the condensing capability is reduced.